The Immunocompromised Patient Flashcards
What is an immunocompromised host?
Immunocompromised host – state in which the system Is unable to respond appropriately and effectively to infectious microorganisms. This is due to a defect in one or more components of the immune system.
What is immunodeficiency?
Immunodeficiency is caused by a defect in one or more components of the immune system such as those in this picture.
What is PID (primary immunodeficiency)
PID – occurs due to congenital disorder – from an intrinsic gene defect resulting in a missing protein, missing cell and non-functional components. – can be autosomal of x-linked.
What is SID (secondary immunodeficiency)
Secondary immunodeficiency – this is acquired – due to an underling disease/treatment leading to a reduction in production/function of the immune components or an increase in the loss or catabolism of immune components.
When should immunodeficiency be suspected?
Severe – life threatening
Persistent – persists even when using standard treatment
Unusual – site and type of organism (opportunistic)
Recurrent – keeps coming back after treatment
Other than infections what else does PID make you susceptible to?
Not only does PID make you susceptible to infections but also to cancer as the immune system plays an important role in preventing cancerous cells from surviving.
How does the age Immunodeficiencies present at give insight to the type of deficiency they have?
Onset < 6 months highly suggests a T-cell or phagocytes defect (not antibody as currently receiving antibodies from mother in breast milk)
Onset between 6months-5 years often suggests a B cell/antibody or phagocyte defect
Onset > 5 years old and later in life usually suggests a B cell/antibody/complement r secondary immunodeficiency.
What type of deficiency are most PIDs and give some examples
The majority (65%) of PIDs are antibody deficiencies. • X linked agammaglobulinaemia or Bruton’s disease – cannot produce antibodies due to a defect in B cell maturation – X linked condition • Common variable immunodeficiency (CVID) – very low level of IgG, IgM and IgA • Selective IgA deficiency – mostly asymptomatic • IgG subclass deficiency – mostly asymptomatic
What is combined T and B cell deficiency?
• Severe combined immunodeficiency – SCID – inhibition of T cell development – called combined because if T cells are inhibited then so will B cells.
What Phagocytic defects are there?
- Chronic granulomatous disease – phagocyte can’t produce reactive oxygen species so cannot do a respiratory burst
- Severe congenital neutropenia
- Cyclic neutropenia
What is Wiskott-Aldrich syndrome?
Wiskott-Aldrich syndrome – x linked condition characterised by eczema low platelet count (thrombocytopenia) and immune deficiency caused by decreased antibody production and inability of T cells to become polarised making it combined.
What is DiGeorge syndrome?
DiGeorge syndrome – autosomal dominant caused by a deletion of part of chromosome 22 causing a range of congenital malformations including immunodeficiency
What is Hyper IgE syndrome?
Hyper IgE syndrome – abnormal neutrophil chemotaxis due to decreased production of interferon gamma by T lymphocytes
What is Ataxia-telangiectasia
Ataxia-telangiectasia – autosomal recessive with many symptoms but the immunodeficiency side of things is caused by low antibody production and low Lymphocytes, particularly T cells
How does Chronic granulomatous disease commonly present?
Skin infections
Pulmonary Aspergillosis – Halo signs in HRCT scan from nodules in the lung – chronic fungal infection of the lungs. This is from opportunistic infections from Aspergillus species (fungus).
